On the one hand, the answer is clear: if you want to save some money and not lose much (or any) performance, it will be reasonable to redistribute your budget and buy DDR2 memory, which is still cheaper. Also, the relatively old overclocker DDR3 memory kits for other platforms work well with Phenom II, and in most cases they even significantly exceed their recommended frequencies.

http://ixbtlabs.com/articles3/mainbo...3-roundup.html